Conventional bricks, also called compressed earth blocks (CEBs), in use today are typically ceramic blocks made of kiln-fired materials, such as clay. On a small scale, clay bricks are formed in a mold, which is called the soft mud method, and on a large, commercial scale, clay bricks are made by extruding clay through a die and wire-cutting the bricks, which is called the stiff mud process. Sometimes the clay is mixed with water and these dampened clay bricks are subjected to high pressures. Such bricks are highly resistant to weathering and therefore well-suited for construction of exterior walls. The shaped clay is dried and fired to achieve the final brick shape with the desired strength. The firing process is usually done by a continuously fired kiln, in which the bricks move slowly through the firing on a conveyor belt or the like. This enables production of an essentially indefinite number of bricks which exhibit consistent physical characteristics.
Other types of building materials are sometimes used for wall construction, including wood, vinyl, stucco, and/or stones. For many years stones or natural rocks were thought by many in the building trade to be superior to bricks both functionally and aesthetically. However, stones for use in wall construction are typically heavier than bricks and must normally be sculpted into the proper shape. Some prefer stone walls because the stones are shaped and colored more naturally and randomly, and provide less of an “assembly-line” look, and more aesthetically pleasing look. However, using such irregular shapes in construction of a wall introduces difficulties in addition to regular building considerations. For example, irregular shapes may require individual stones to be broken/sculpted in order to finish the corner or side of a wall or to fit with other stones in the construction of a wall. However, this is very difficult, time-consuming, and wasteful because stones and rocks tend to break and crack irregularly. For this and other reasons, the commercial success of “natural” stone walls remains limited, despite their aesthetic, functional, and other advantages.
Attempts have been made to produce manufactured stone walls which do not require the use of sculpted or reshaped stones. Such attempts have included cast stone “tiles” which are cast from aggregate and/or ground stone and are plastered to the sides of a building to provide the illusion of natural stone walls. However, such stone tiles are not easily used in conjunction with conventional bricks.
A recent trend in home building involves the use of varying external materials to build a single wall, such as areas of brick and areas of wood paneling, all on one wall surface. However, until recently, there was no known method of effectively combining bricks and stones in the production of a wall. The regularity of bricks and the irregularity of stones makes it very difficult to integrate the two into a single wall structure, even with the use of the aforementioned manufactured stone tiles. Unlike stone tiles, conventional bricks are laid on top of each other a certain distance from the side of a building to create a wall. The space between bricks and the side of a building has the advantage of acting as an insulating space. Such a space is not possible with stone tiles, which are plastered to the side of a building. Additionally, the stone tiles may not be easily used in conjunction with bricks in building a structure, since the distance the stone tiles extend from a structure is much less than the distance bricks extend from a structure, creating aesthetic and structural problems.
Some of the problems faced with manufactured stone tiles are addressed in Applicants' U.S. Patent Application Publication No. 2008/0110116, which is incorporated herein by reference. The '116 publication describes a system of manufactured stone blocks which have at least one surface with a simulated-stone appearance and having a length, a height, and a depth determined based on a compatibility factor derived from the length, height, and depth of a conventional brick and the width of the mortar joint located between conventional bricks. The compatibility factor is used to derive a dimension equation for the length, height, and depth and the dimension equations are used to fabricate the manufactured stone blocks.
The manufactured stone blocks of the '116 publication enjoy many of the benefits of conventional bricks, such as having a space between the manufactured stone block wall and the side of the building to act as an insulating space, while also providing the appearance of a “natural” stone wall. Additionally, the stone blocks are dimensionally compatible with conventional bricks and manufactured stone block sections may be easily interspersed into a brick wall. Further, masons do not need to undergo substantial amounts of training to learn the method of building structures out of the manufactured stone blocks, since they are laid in a similar manner to conventional bricks with mortar and typical mortar joints, unlike stone tiles which required a mason to learn a new method of building a structure.
However, the manufactured stone blocks of the '116 publication may not be sufficient to simulate the appearance of all natural stone walls. For example, as shown in FIGS. 1 & 2, some natural stone structures are built in a “dry-stack” construction without the use of mortar or grout in visible joints as found in brick walls. However, the mortar and grout joints are desirable to hold the blocks together and add strength to the walls. Accordingly, there is a need for a manufactured stone block which enjoys the benefits described in the '116 publication and utilizes the strength advantages offered by mortar joints between stone blocks, while also simulating the appearance of a dry-stack stone wall. Additionally, some forms of natural stone construction are not amenable to the rectangular block form disclosed in the '116 publication. For example, as shown in FIG. 2, in ledgestone walls and other types of rock walls it is often desirable to use stones which are not uniformly rectangular. Accordingly, there is also a need for a manufactured stone block system which enjoys the ease of use of the manufactured stone system of the '116 publication, while also maintaining the often desired aesthetic appearance of irregularly, non-rectangular shaped rocks.
These needs are addressed by the stone fabrication system of the present invention. A hidden mortar joint is included in the manufactured stone blocks which is not visible on the external face of the brick including the natural stone appearance in order to provide the appearance of a dry-stack wall, while also providing a joint for application of mortar or grout to hold the manufactured stone in place and provide strength to the wall. Additionally, multiple simulated stone portions may be molded into the externally facing side of the manufactured stone block, thereby providing the dimensional compatibility advantages described in the '116 publication while also providing the appearance of irregularly shaped stones.